hpmv¶
Computes a matrix-vector product using a Hermitian packed matrix.
Description¶
The hpmv
routines compute a scalar-matrix-vector product and add the
result to a scalar-vector product, with a Hermitian packed matrix.
The operation is defined as
where:
alpha
andbeta
are scalars,A
is ann
-by-n
Hermitian matrix supplied in packed form,x
andy
are vectors of lengthn
.
API¶
Syntax¶
void hpmv(queue &exec_queue,
uplo upper_lower,
std::int64_t n,
T alpha,
buffer<T,1> &a,
buffer<T,1> &x,
std::int64_t incx,
T beta,
buffer<T,1> &y,
std::int64_t incy)
hpmv
supports the following precisions and devices.
T |
Devices Supported |
---|---|
|
Host, CPU, and GPU |
|
Host, CPU, and GPU |
Input Parameters¶
- exec_queue
The queue where the routine should be executed.
- upper_lower
Specifies whether A is upper or lower triangular. See Data Types for more details.
- n
Number of rows and columns of
A
. Must be at least zero.- alpha
Scaling factor for the matrix-vector product.
- a
Buffer holding input matrix
A
. Must have size at least (n
*(n
+1))/2. See Matrix and Vector Storage for more details.The imaginary parts of the diagonal elements need not be set and are assumed to be zero.
- x
Buffer holding input vector
x
. The buffer must be of size at least (1 + (n
- 1)*abs(incx
)). See Matrix and Vector Storage for more details.- incx
Stride of vector
x
.- beta
Scaling factor for vector
y
.- y
Buffer holding input/output vector
y
. The buffer must be of size at least (1 + (n
- 1)*abs(incy
)). See Matrix and Vector Storage for more details.- incy
Stride of vector
y
.
Output Parameters¶
- y
Buffer holding the updated vector
y
.